Power transmission mechanism for window regulators



A MACKMANN 2,651,212

Nnow REGULAToRs l sep-f. s, 1953 POWER TRANsmssmN MECHANISM FOR wr Filedoct. 11, 195o A 2 Sheets-Shed'. l

f INVENTOR. /V/ZZZ/r s. n y ME i d 2,

SPL 8, 1953 A. MACKMANN 2,651,212

POWER TRANSMISSION MECHANISM FOR WINDOW REGULATORS Filed Oct. ll, 1950 2Sheets-Sheet 2' l I INVENTOR.

BY l f Patented Sept. 8, 1953 oN1MEcHANrs-M Fons. A EGULA'roRs PGWERTRANSMISSI WINDGW R Arthur Mackmann, Chicago, Ill., Cleveland, Ohio,

Corporation, Virginia OFFICE assigner to Hupp a corporation ofApplication. october'- 11, 195o, serial No. listersA 1.3 claims. (ci.ris-42s This. invention relates to window regulators andthe like, andespecially to power transmis.- sion mechanisms for window regulatorsinauto'- motive vehicles wherein the windows are raised and 1owered byrotary power vmeans such esta reversible electric motor.

Among the problems. which are. encountered in n the design of powertransmission mechanisms. of the type described is. that of achieving, a.large reduction inspeed from a. power source such as a small, high-speedmotor to the window actua-.ting linkage,l and simultaneously preventingjam.- ming or locking of. the mechanism when the. window reaches itsstalled position. The. limitation of space and the necessity :for quickoperation of the windowsl make it. necessary that the power transmissionmechanism be. compact and have a. relatively high. eiiciency. Howeverlit. is. essential that the mechanism. be. so constructed as to preventreversing action. when force is ap.- plied directly to the` window 'sothat it wi1l...be impossible to open the, window except by actuationofthe power means.

It is` therefore an object of the present invention toV provide a powertransmission. `mechanism for anA automotive window regulator which willbe` extremely compact in construction, andwill have suiiciently high.speed reduction. without danger of locking or jamming of the, mechanismwhen the window is being tightly seated at the terminal positions.

It is another object to provide a transmission mechanism as describedhaving a relatively high eiiciency without the. attendant danger oi.re,- versibility of operation, thus preventing opening of the window bya force applied directly thereto. Itis a further object to provideafpower trans.- mission unit as an integral part of a. window regulatormechanism as described, which. is of relatively simple design andconstruction and Vwhich can be manufactured as a, package .unit forcooperation. with the standard types of window regulator linkages now inconventional use..

Other objects, features, present invention will become apparent from thesubsequent description taken in conjunction with the accompanyingdrawings.

In1 the drawings:

Figure 1 is a. plan view of a portion. of the power transmissionmechanism of this.. invention with the cover plate removed;

Fig. 2 is a sidey cross-sectional view taken along the line 2-2 of Fig.1 and` showing the worm train and associated parts;

Fig. 3 isa cross-sectional view taken along. the

and` advantages of the l line 3"- 3 of Fig. 1 andl showing, the wheeland cover plate;

Fig. 4' is ak detail' view of the pinion and its associatedlgearsector;l Fig. 5 is a cross-sectional view similar to Fig. .3 but showingamodiiication of the power transmission unit;

Fig.. 6 is a -crosssectional view similar to Fig. 3 butr showing. aSecond modification .of the. cover plate and shaft support;

Fig. 7' is a cross-sectional viewsimilar to Fig. 3 and' showing stillanother modication of the shafty supporting means; and

Fig. 8 a. cross.-sectional view similar to Fig. 3 showing a fourthmodification of ther power transmissionv The power transmissionmechanism of this inhousing, worm or more swing- K'Ihe mechanism `ingsleeves are secured within spaced apertures inet designated)- atopposite -side wallsv of housing extension I8. Bearing 2| is held inposition by a shoulder 23 engageable with the inner surface of thehousing, and a dome-shaped plug 24, preferably of spring-like material,is inserted outwardly of bearing 22 to hold the latter in position aswell as to weather-seal the housing opening. Worm gear I'I is rotatablymounted in the side wall of housing I by means of a bearing sleeve 25.The hub 26 of Worm gear I1 extends through the housing I5 and pinion onthe outer end of hub 26. A shoulderl 21. on bearing holds the side 28 ofworm gear I.| yin spaced relation with the inner surface of the housingI5. The oppositeside'rof is provided with a circular recess floorportion 2B recess being concentric with hub 2B'.-

A cover plate 32 is provided for the open endof the housing, and thiscover sion 33 which encloses 'the worm I6 within the extension I8 of thehousing.` The' cover plate 32 is iush with the peripheral surface ofhousing I5 and is attached at spaced points thereto by means of bolts orscrews '34 which extend through the housing and serve also to attach thehousing to mounting bracket I3 by means of threaded washers or similarfasteners 35' attached to the bracket. Smaller bolts 36 serve to holdthe extension tension I8. A plurality'of projections 31 may be formed onthe housing to hold it in proper spaced relation to the mounting bracketand gear sector. The cover 32 is further provided with a circular havinga` fiat I4 is formed and an annular side wall 3l, this 33 of the coverto housing exj worm gear I1 of a gear having 120 teeth and the pinion'above'aremerely illustrative, and that the principles of this;invention herein described are applicable to power transmission unitshaving other proportions than those in the illustrated embodiplate hasan extenprojection extending 'inwardly therefrom concentric with therecess on worm gear I1. This projection has an annular sidewall 38 and adome-shaped intermediate 'portion 39, an annular portion 4I ofrelatively sharp radius connecting the wall and dome-shaped portions;Wall portion 38 is adapted to be 'in engagement with side wall 3I of theworm gear recess, and annular bearing portion 4I is adapted to engagethe floor portion 29 of the recess. It will thus be seen that the coverprojection will serve to hold worm gear I'I against both radial andaxial movement, since any tendency to move radially will be resisted 'bywall 38 of the projection and any axial' movement will be resisted bybearing portion 4I. This construction greatly lessens the possibility ofnoise and vibration due to radial motion' of the worm gear, and resiststhe effect of thrust forces due to the angularity of the worm gear'teeth.

From the structure thus far described 'it will be apparent that uponoperative rotation of shaft I9 `in either direction worm gear I1 will berotated, thus rotating pinion I4 and moving gear sector II to actuatethe window `linkage arms to raise or lower the window. Because of therelatively high speed motor which must necessarily be used 1t 1snecessary that a speed reduction of about 400:1 take place between theshaft I3 and the gear sector I I. It has also been found essential, dueto the space limitations involved, that a pinion I4 of relatively fewteeth must be used in order to achieve proper results when theconventional size gear sector',V ordinarily the equivalent of a gearhaving about 120 teeth, is used. The present f invention combines theseprinciples of operation by providing artwo step gear reduction in whicheach step provides about half of the necessary speed reduction. Moreparticularly, a construction is provided inv which the speed ratiobetween worm IB and worm gearf l1 is approximately 20:1, and `the speedratio between pinion I4 and gear sector II is likewise vversing themotor.

' worm "used for twill normally be 'the worm gear betweenpinion nient. l

The efficiency of the worm and worm gear are preferably of suchcontrolled magnitude as to be relatively close to the margin ofnon-reversibility at rest when a rotary force is applied to the wormgear greater than the normal force from the connected load. It has beenfound that the the worm and worm gear is such that jamming or locking ofthe threads of the worm and the worm gear when the window reaches itsterminal position is substantially prevented, while at the same time theratio is high enough to prevent reversible operation of the mechanism byforce applied directly to the window. It has also been found that theparticular helix angle A used for the threads of worm I6 have a decidedeffect on the reversibility of the mechanism as well as on the tendencyto jam or lock when full stalling torque power is applied, that is, whenthe window reaches a terminal position while power is still applied tothe motor. This may be more clearly understood from an examination ofthe figures, whereby it will be seen that if too small ahelix angle isused the frictional wedging action of the helix threads upon the wormgear teeth will be so great when full stalling torque is applied as tomake itextremely difficult to dislodge the worm upon re- Likewise, whenworm gear I'I attempts to drive worm I5 (for example, when force isapplied directly to the window) too great a helix'angle will allow thecomponent of force parallel to the helix threads to overcome thecomponent normal to the threads, thereby driving shaft I9.

The construction of this invention provides a I6 having a helix angle Aapproximately equal to the friction angle between the worm and worm gearteeth, as determined by the materials these two parts and the finishesprovided on the contacting surfaces. This angle l in the range between 5and 15. and it has been found that a helix angle within these limitsavoids both the possibility of jamming at full stalling torque and thepossibility of reversible operation. It will be noted that because ofthe angularity of the axis of shaft I3 to the plane of Worm gear I'I itis necessary to cut the'teeth on the worm gear so as to compensate forthis angularity; for example, with a worm helix angle A ci 4l2 41' andan angularity lBof the shaft I9 of 7 4l', the angularity C of teethshould be 5, as shown in Fig. 2. v s 'l In order to further assureagainst the reversibility of operation of the mechanism, as well as toprovide smooth tooth-to-tooth involute action I4 and gear sector I I, along-and short addenda, type of tooth form is used for these twoelements of the train. Asshown in Fig. 4, this construction provides arelatively long on each tooth of pinion I4 and a relatlvely sho-rtaddendum E on each gear sect-r well known, this type of gearconstruction is particularly suited for one-way gear trains whereindriving pinions of relativelyfew teeth are meshed with gears havingrelatively manyteeth. This tooth construction results in an arc ofaction F comprising a relatively short arc of approach G anda relativelylongarc of recession H, so that while smooth -action is achieved whenthe pinion isdriving the gear, the teeth will tend to lock` if gear IIattempts to drive pinion I4, since in this event the long arc H willbecome the arcof approach, resulting in greater friction.

It will thus be seen that when the speedratio of the worm and worm gearandthe helix angle of the worm are such as to approach the margin ofreversibility from rest, the inherent tendency of gear I I and pinion I4to lock will serve to prevent reversible operation of the mechanism.This cooperative action between the piniondrive and the worm drive playsan important role in the illustrated embodiment wherein the `12 41 wormhelix angle and the worm speed reduction of approximately 20:1 are closeto the margin of reversible operation from rest.

Fig. illustrates a modification of the power transmission unit I2 havingelements similar to the embodiment of Figs. 1 to 4 but wherein theembodiment. The annular wall .portion 53, which corresponds to wallportion 3I of the previous modificati-on still serves, however, as aradial bearing for the worm gear 54. The worm gear has a splined bore 55within which is staked the inner end of pinion shaft 56. For thispurpose the teeth of the pinion are cut along the full length of shaft56, the outer portions 51 of the teeth being of full size and acting asthe drive pinion, and the remaining lengths 58 of the teeth being ofsmaller outside diameter and acting as a spline staked in bore 55. Asteel sleeve 59 is tightly iixed on tooth portions 58 of the pinionshaft, and this sleeve is'journaled in a bearing 6I, preferably ofbronze, which is mounted in the housing. A

In order to take the axial thrust loads on worm gear 54 and itsassociated parts,`a bearingblock 62 is disposed between the dome-shapedportion 63 of cover 52 and the worm gear. A iat annular raised thrustsurface 64 is formedon-worm gear 54 immediately surrounding the splinedbore 55. Bearing block 62 is provided with an upper surface 65 having aconvex shape of curvaturecor.- responding to that of dome-shaped coverportion 63. The opposite side of bearing block 62V has an annular atsurface 66 in Hush engagement with the portion 64 of the wor-m gear, anda clearance recess 61 is provided in the, Ibearing block adjacent shaft56. It will be seen therefore that outer surface 65 of the bearing blockwill be engageable with the inner, surface ofA domeshaped cover portion63, the latter holding the bearing block in concentric relation with theworm gear. Inner surface 66 of the bearing block will bear againstannular portion 64 of the worm gear, and the bearing block will thusserve as an axial thrust bearing for the 'Worm gear andv its associatedparts. t ff f Fig. 6 illustrates a second modification' of the bearingstructure which is generallysimilar to that of shaped trally locatedretaining recess 69 which is concave inw-ardly. The worm gear 1I isstaked to pinion shaft 12 in a manner similar to that shown in Fig. 5,and the or similar anti-friction member 16 is held in operative position`between recesses 69 and 15 and will thus act as a thrust bearing forshaft 12. It will be observed that due to the concontact the worm gearas in the previous embodiment, thus also resisting some of the radialforces.

Fig. '1 shows a further modification h-aving a cover plate 18 `of flatshape adjacent worm gear 19:. The cover plate is not in direct contactwith the worm gear and thus worm gear as in the previous embodiment, isprovided with a bore 'which is blind on one end and Within which isfirmly secured a pilot pin 86. The pilot pin extends `outwardly frombore 85 toward the cover, and the bearing block 8| is'provided with aconcentric bearing aperture 81 within which the outerl end 88 of thepilot pin is received. Worm gear 19 is further provided with a flatannular surface 89 surrounding the pinion shaft, and the inner end ofIbearing block 8I has a fiat annular thrust bearing surface 9I inengagement with surface 89. The bearing block 8'I thus serves both as athrust and a radial bearing member for the Worm gear and the pinionshaft.

-Fig. 8 is another modification generally similar to that of Fig. 7 andhaving a bearing block 92 corresponding to the bearing block 8|V of Fig.'7. However, the diameter of bearing block 92 is in spaced relaposedwithin bearing A spherical ball member 91 is disposed at the bottom 98of bearing aperture 95, the bottom preferably being of flat shape. Thesize of spherical member 91 99 of the stub 96 will be in as a radialbearing for the shaft 93 and its associated parts, and the sphericalmember 91 will serve as a thrust bearing therefor.

the proper Scope or fair meaning of the subjoined claims.

meenam 75 f i claim:

1'.` I'r'i a. power: transmission system for a wim dow" regulator` or,`the like, a worm adaptedA to'b'e connected-to a rotary driving motonaworm gear driven'by said worm, the helix angle of said worm beingapproximately equal to the friction angle between the two materials ofsaid worm and worm gear, the'efliciency of said worm andv worm gearbeing of such controlled magnitude astotbe relatively close to themargin of non-reversi@ bility at rest when a rotary force is applied tothe worm gear greater than the normal force from the connected load, arpinion rotatablel with said worm gear, and a driven gear meshing withsaid pinion andV adapted to be connected to the operating linkage of awindow regulator or the like, the teeth on said pinion and driven gearbeing of the longeand-short addenda type,- wheres by' reversibility ofoperation of the entire gear trai-n from' a state of rest issubstantially prevented when a force from' a foreign source is applieddirectly to the window.

2i The combination according toclaim 1,. iurther provided with a shaftfor said worm rotatably mounted adjacent said wor-m. gear and adapted tobe connected to a rotary power source, the axis of said shaft `being.angularly displaced from the plane of said worm gear.

3. In a power transmission system for a window regulator or the like, aworm adapted to be connected to a rotary driving motor, a worm geardriven by said worm, the axis of saidA worm being angularly displacedfrom the plane of said worm gear, the eihciency oiV said worm and wormgear being of such controlled magnitude as to be relatively1 close tothe margin of non-reversibility at said worm gear, and a driven gearmeshing with said pinion and adapted to be connected to the operatinglinkage of a window regulator or the like, the' speed ratio bei-,weensaid pinion and driven gear being substantially equal to said worm andworm gear ratio, the teeth on said pinion and driven gear being of thelong-and-short addenda type, whereby the meshing teeth on said pinionand driven gear have a relatively short arc of approach and a long arcof recession.

4. In a power transmission 'system for al window regulator or the like,a worm adapted to be connected to a rotary driving motor, a worm geardriven by said worm, the helix angleof said worm being approximatelyequal to the friction'v angle between the two materials of said` wormand worm gear, a pinion rotatable with said worm gear, and a driven gearmeshing with said pinion and adapted to be connected to the operatinglinkage of a window regulator or the like, the teeth on said pinion anddrivenV gear being of the long-and-short addenda type, whereby themeshing teeth on said pinion and driven gear have a relatively short arcof approach and a relatively long arc of recession.

5. The combination according .to claim 4, the helix angle of said worm'being greater than 5, 'whereby jamming of the teeth on `said worm andworm gear when full stalling vtorque is applied is substantiallyprevented.

6. The combination according to claim 4, the overall speed ratio betweensaid worm and said driven gear being approximately 400221, said speedratio being substantially equally divided between the speed ratios ofthe worm and worm gear and the pinion rand driven gear.

'7. In a power transmission unit'for a window regulator or the like, 'anopen-sided housing, a 75 worinI rotatably adapted to be connected torotary driving means, avworm. gear within said housing and operativelymeshing with said worm, a pinionk on one side of said worm gear androtatable therewith, said pinion being adapted for a driving connectionwith the operating linkage of a window regulator or the like, a recesson the opposite side of said worm gear and concentric therewith, saidrecess having acircular side wall portion and a flat iioorportion, and acover for the open side of said/housing, said cover having an annularinner projection engageable withY said wall portion and said doorportion, whereby said projection holds said worm gear against both axialand radial movement.

8. n a power transmission unit for a window regulator or the like, anopen-sided housing., a worm rotatably mounted in said housing andadapted tobeconnected to rotary driving means, a worm gear within saidhousing and operatively meshing with said worm, a pinion on one side ofsaid worm` gear and rotatable therewith, said pinion beingl adapted fora driving connection with the operating. linkage of a window regulatoror the like, a recess on the opposite side of said worm gear andconcentric therewith, said recess havingV a circular side wall portionand a dat floor portion, a cover for the open side of said housing, saidcover' having an annular inner projection engageable with said wallportion to hold said worm gear against radial movement, an inwardlyconcave dome-shaped portion on said cover, and a bearing block' betweensaid cover and said worm gear, said bearing block having an. outerconvex surface' engageable by said domeshaped cover portion and' aninner flat surface eng'ageableV with the floor portion of said worm gearrecess, whereby 'said worm gear is held against axial movement'.

9. In a. power transmission unit for a window regulator or' the liker anopen-sided housing, a worm rotatably mounted in said housing and'adapted to be connected to rotary driving means, a rotatable shaftextending through said housing, a worm gear mountedV on lsaid shaftwithin said housing and operatively meshing with said worm, a recess onone side of said worm gear, said recess having a circular side wallportion, a pinion mounted on said shaft and extending outwardly of saidhousing, said pinion being adapted for connection with the operatinglinkage of a window regulator orthe like, a retaining recess at one endof saidV shaft, a cover for the open side of said housing, a retainingrecess on the inner surface of said cover and yconcentric with saidshaft vretaining recess, and a spherical member between said cover andsaid shaft and retained by said retaining recesses, whereby said shaftis heldl against axial and radial movement.

10. The combination according to claim 9, said cover having an annularinner projection engageable with said wall portion to further hold saidwor-m gear against radial movement.

11. In aV power transmission unit for a window regulator or the like,.an open-sided housing, a worm rotatably mounted in said housing andaxiaptedto be connected to rotary driving means, a rotatable shaftextending Vthrough said housing, a worm gear mounted on said shaftwithin said housing. and operatively meshing with said worm, a pinionmounted` on said shaft and extending outwardly' of said housing, saidpinion being adapted for a vvdriving vconnection with the operatinglinkage of a window regulator or the like,

mounted in said. housing; and

a cover for the open side of said housing, a beargear, the helix angleof said worm being approxiing block mounted on said cover and extendingmately equal to the friction angle of the two inwardly therefrom, said:bearing block having materials used for said Worm and worm gear, the aflat annular surface engageable with the adjaeiiciency of said worm andworm gear being of cent side of Said Worm gear shaft, and a ybearingsuch ycontrolled magnitude as to be relatively close aperture withinsaid bearing block, one end of to the margin of non-reversibility atrest, a pinsaid shaft being disposed within said aperture. ion rotatablewith said worm gear, and a driven 12. In a power transmission unit for awindow gear meshing with said pinion and adapted to be regulator or thelike, an open-sided housing, a connected to the operating linkage of awindow worm rotatably mounted in said housing and regulator or the like,the teeth of said pinion and adapted to be connected to rotary drivingmeans, driven gear being of the long-and-short addenda a rotatable shaftextending through said housing, type with said pinion havingapproximately six a worm gear mounted on said shaft within said teeth,the overall speed ratio between said Worm housing and operativelymeshing with said Worm, and said driven gear being approximately 400:1,

a pinion mounted on said shaft and extending said speed ratio beingsubstantially equally di- OutWaldly 0f Said hOuSng, said pinion beingvided between the speed ratios of the worm and adapted for a drivingconnection with the operatworm gear and the pinion and driven gear.

ing linkage of a window regulator or the like, a ARTHUR MACKMANN. coverfor the open side of said housing, a bearing block mounted on said coverand extending References Cited in the le of this patent inwardlytherefrom, a bearing aperture at the UNITED STATES PATENTS inner end ofsaid bearing block, one end of said Shlf being disposed within saidaperture, and Number Name Date an anti-friction member within saidbearing 243,634, 5811815.61? al June 28,1881 aperture between the end ofsaid shaft and the 1149206 Mechlmg Jr- Aug- 10 1915 bottom of theaperture. 1,711,500 Hutchens May 7, 1929 13. In a power transmissionsystem for a Win- 1,839,368 Baum Jan. 5, 1932 dow regulator or the like,a worm adapted to be 2,173,660 Perkins Sept. 19, 1939 connected to arotary driving motor, a Worm gear 211761956 000k et al 0G11- 24, 1939driven by Said worm, the axis of said Worm being 2,1901741 SylvesterFeb- 20, 194O

